The present invention relates to an IC card system with an IC card terminal.
When cash handling equipment such as an electronic cash register is used, a mechanical key lock mechanism is arranged to prevent a third party other than an authorized operator from using the equipment. In other words, the electronic cash register will not operate unless the authorized operator releases the key lock using a master key, thus preventing illegal use of the register.
A conventional key lock system of this type can also be applied to an IC card terminal which is used with an IC card.
The conventional key lock system, however, has the following drawbacks:
1. Since the key lock mechanism is a mechanical one, the key can be easily copied.
2. A key lock mechanism must be arranged independently of the mechanism inherent in the system, and thus the overall system becomes expensive.
3. Since the key must be held in a corresponding key slot to continuously release the key lock state while the system is being operated, the key may be stolen. In addition, the number of keys needed is the same as that of the IC card terminals.
In an IC card system, countermeasures against illegal use must be provided in the same way as for the electronic cash register. However, an effective countermeasure has not, so far, been realized.